fix(cli): doom emacs: command not found

Being the flawless professional that I am, I forgot to include the
source code for `doom emacs` in 7f6a2d2.

Fix: #8429
Amend: 7f6a2d284e

lisp/cli/emacs.el

@@ -0,0 +1,119 @@
+;;; lisp/cli/emacs.el --- launching Emacs and sandboxes -*- lexical-binding: t; -*-
+;;; Commentary:
+;;; Code:
+
+(require 'doom)
+(require 'doom-cli)
+
+;;
+;;; Variables
+
+;; None yet!
+
+
+;;
+;;; Commands
+
+(defcli! emacs
+    (;; TODO Implement sandbox functionality post-3.0
+     ;; (daemon?     ("--daemon"))
+     ;; (window-type ("--gui" "--tty"))
+     ;; (version     ("--with-emacs" version))
+     ;; (doomversion ("--with-doom" version))
+     ;; (profile     ("--profile" name))
+     (repl?  ("--repl") "Launch an elisp REPL")
+     ;; &multiple
+     ;; (calls  ("-f" "--funcall" fn))
+     ;; (loads  ("-l" "--load" file))
+     ;; (evals  (     "--eval" form))
+     &context context
+     &input input
+     &rest args)
+  "Launch Doom Emacs or an Emacs sandbox
+
+Opens from bin/doom's parent directory.
+
+Keep in mind there is some overhead opening Doom this way. For the best
+performance, it is best to run Doom out of ~/.config/emacs or ~/.emacs.d."
+  :benchmark nil
+  (if repl?
+      (if input
+          ;; Evaluate piped-in text directly, if given.
+          (eval (read input) t)
+        (doom-emacs-repl context))
+    (let* ((tempdir  (doom-path (temporary-file-directory) "doom.run"))
+           (tempemacsdir (doom-path tempdir ".emacs.d")))
+      (delete-directory tempdir t) ; start from scratch
+      (make-directory tempemacsdir t)
+      ;; HACK: So that Emacs doesn't lose track of local state, like user fonts,
+      ;;   configs, or binscripts, we symlink these to the sandbox.
+      ;; REVIEW: Use `--init-directory' when we drop 29 support OR when Doom is
+      ;;   in bootloader mode.
+      (dolist (dir (list (cons "XDG_DATA_HOME"   ".local/share")
+                         (cons "XDG_STATE_HOME"  ".local/state")
+                         (cons "XDG_BIN_HOME"    ".local/bin")
+                         (cons "XDG_CONFIG_HOME" ".config")
+                         (cons "XDG_CACHE_HOME"  ".cache")))
+        (let* ((source (expand-file-name (or (getenv (car dir)) (expand-file-name (cdr dir) "~"))))
+               (target (expand-file-name (cdr dir) tempdir)))
+          (when (file-directory-p source)
+            (unless (file-symlink-p target)
+              (make-directory (file-name-directory target) t)
+              (make-symbolic-link source target)))))
+      (with-temp-file (doom-path tempemacsdir "early-init.el")
+        (prin1 `(progn
+                  ;; Restore sane values for these envvars
+                  (setenv "HOME" ,(getenv "HOME"))
+                  (setenv "EMACSDIR" ,doom-emacs-dir)
+                  (setenv "DOOMDIR"  ,doom-user-dir)
+                  (setenv "DOOMPROFILE" ,(getenv "DOOMPROFILE"))
+                  (setq early-init-file ,(doom-path doom-emacs-dir "early-init.el"))
+                  (load early-init-file nil (not ,init-file-debug) 'nosuffix))
+               (current-buffer)))
+      (exit! (format "HOME=%S %s %s"
+                     tempdir
+                     invocation-name
+                     (combine-and-quote-strings args))))))
+
+
+;;
+;;; Helpers
+
+(defun doom-emacs-repl (_context)
+  "Launch a rudimentary Elisp REPL."
+  ;; I wrote this for fun; not with any serious intention of adding a
+  ;; fully-fledged REPL to the Doom CLI. Still, I occasionally need to check
+  ;; something, and once this has nix integration and can sandbox Emacs versions
+  ;; separately, it may be useful for quick tests and demos.
+  (let (form)
+    (while (setq form (read-from-minibuffer "(elisp) $ "))
+      (when (member form '(":quit" ":q"))
+        (print! "\nGoodbye!")
+        (exit! 0))
+      (let (debug-on-error)
+        (condition-case e
+            (print! "%S" (eval (read form) t))
+          (error
+           (let* ((n 0)
+                  (frame (backtrace-frame n))
+                  (frame-list nil)
+                  (in-program-stack t))
+             (while frame
+               (when in-program-stack
+                 (push (cdr frame) frame-list))
+               ;; (when (eq (elt frame 1) 'doom-run-repl)
+               ;;   (setq in-program-stack t))
+               (when (eq (elt frame 1) 'doom-run-repl)
+                 (setq in-program-stack nil))
+               (setq n (1+ n)
+                     frame (backtrace-frame n)))
+             (let* (;; (depth doom-cli-log-backtrace-depth)
+                    (print-escape-newlines t))
+               (print! (error "There was an unexpected error"))
+               (print-group!
+                 (print! "%s %s" (bold "Message:") (error-message-string e))
+                 (print! "%s %S" (bold "Details:") (cdr e))))))))
+      (terpri))))
+
+(provide 'doom-cli '(emacs))
+;;; emacs.el ends here